The subject invention is directed toward a screen printing method which allows the printing fluid to be applied in selected variable thicknesses.
The method is especially suited for applying patterns of adhesive to plastic sheets used for door protectors in the automotive industry and will be described with reference thereto; however, the invention is capable of broader application and could be used for applying many types of paints, adhesives, and the like in predetermined patterns to a variety of different sheet materials used for many purposes.
In commonly assigned U.S. Pat. Nos. 4,588,627; 4,865,791; 4,696,848; and 4,873,132, there are disclosed protective plastic sheet devices commonly used in the automotive industry as water deflectors or shields for the interior of passenger compartment doors. The water deflector sheets are generally held in place by pressure sensitive adhesive applied to the sheets in predetermined patterns by, for example, a screen printing process. Depending on various factors, including the shape and nature of the shield, as well as the shape and nature of the door interior surface to which the shield is to be applied, it has at times been desirable to coat the adhesive in thicker layers in some areas. Such application of the adhesive has not been possible using normal screen printing techniques of the type generally used for adhesive application.